Tafsir of Al Imran 3:160

This is an independent sentence, presented by way of varying the discourse as an honor to the believers. It is intended to necessitate reliance upon Him, to encourage obedience to Him—through which one becomes deserving of victory—and to warn against disobedience—through which one becomes deserving of abandonment. It means: if He wills your victory, just as He willed it on the day of Badr, then no one can overcome you. This is expressed through the negation of the genus, which systematically includes all individuals who could be "overcomers" in essence and attribute. It is therefore more eloquent than saying "no one will overcome you," as the latter only indicates the negation of the attribute itself.

As the Sheikh al-Islam stated, although the explicit wording of the noble arrangement indicates the negation of their being overcome without addressing the negation of equivalence—which is what the context requires—what is understood from it definitively is the negation of equivalence and the affirmation of dominance for the addressees. For if you say, "There is no one more generous or virtuous than such-and-such," it is inevitably understood that he is more generous than every generous person and more virtuous than every virtuous person. This is a consistent rule in all languages; it is not restricted to explicit negation, but also applies to what is stated by way of interrogative negation, such as in His saying: "And who is more unjust than one who invents a lie against Allah?"—found in many places in the Revelation. We have already pointed out this topic previously.

(And if He abandons you) i.e., if He wills your abandonment and withholds His aid from you, as He did on the day of Uhud. It has also been recited as "yukhthilukum" (He makes you abandoned), derived from "akhthala-hu" (to cause someone to be abandoned).

(Then who is there to help you after Him?) This is an interrogative of denial, denoting the non-existence of a helper, similar to the negation of the overcomer. It is said: the response to the conditional clause in the first part came as an explicit negation, whereas it did not come as such in the second, out of gentleness toward the believers; He explicitly stated that they could not be overcome, but did not explicitly state that they had no helper, even though the speech implies it.

(After Him) i.e., after His abandonment, or after Allah—meaning if you move beyond Him. In the first instance, "after" is a temporal adverb, which is its primary usage, while in the second, it is a metaphor for place.

(And upon Allah) and not upon anyone else, as indicated by the advancement of the object, (let the believers rely). Those intended are either the genus of believers, with the addressees included primarily, or the addressees specifically by way of shifting the mode of address. In either case, the honor bestowed upon the addressees is clear, alongside an allusion to the reasoning for the necessity of relying upon Him, the Exalted. The "fa" (then), as they have said, is for the ordering of what follows it, or the command thereof, based on what has passed regarding the victory of the believers or their being overcome, contingent upon Allah granting them victory or abandoning them. For knowledge of that necessitates, inevitably, restricting reliance to Him, the Glorified.